Thin-Film Solar Cells Based on Selenized CuSbS₂ Absorber

Area of Science:

• Materials Science
• Solid-State Physics
• Renewable Energy

Background:

• Copper antimony sulfide (CuSbS2) is an earth-abundant material with potential for photovoltaic applications.
• Current CuSbS2 solar cell efficiencies are limited for practical use.

Purpose of the Study:

• To enhance the efficiency of CuSbS2 photovoltaic devices through selenization.
• To investigate the structural and electronic effects of selenium incorporation.

Main Methods:

• Fabrication of porous CuSbS2 films via spray deposition.
• Post-treatment of CuSbS2 films in selenium vapor to create CuSbS2(Se) films.
• Characterization using X-ray diffraction, elemental analysis, J-V measurements, and AC impedance spectroscopy.

Main Results:

• Selenium effectively doped into the CuSbS2 lattice, substituting sulfur with a high substitution rate (>39%).
• A gradient distribution of selenium was observed from the film surface to deeper regions.
• Selenization significantly reduced carrier recombination centers.
• The efficiency of the selenized CuSbS2 device improved from 0.12% to 0.90%.

Conclusions:

• Selenization is a promising technique for improving CuSbS2 solar cell performance.
• The enhanced efficiency is attributed to reduced carrier recombination and optimized band structure.
• This approach offers a viable path towards more efficient earth-abundant solar cells.